Willis to Feature Innovation and Expertise at RIMS 2012

NEW YORK, April 4 2011 – Willis Group Holdings (NYSE: WSH), the global insurance broker, will
showcase its expertise and innovation at the Risk & Insurance Management Society’s (RIMS) 2012 Annual Conference
and Exhibition in Philadelphia April 15-18. This key industry event brings together thousands of insurance buyers
and insurance experts in a unique format for educational, networking and business opportunities.

Willis’ theme for RIMS 2012 is “Being Best Where it Matters Most,” selected
to reflect Willis’ deep industry expertise in a variety of sectors including marine, aviation, energy, construction,
financial services, and property; while underscoring Willis’ global capabilities via its international network.

As an alternative to the exhibition hall, the Willis Coffee Hub will offer delegates a casual place
to meet and network in the Philadelphia Marriott Downtown, 3rd floor. Willis will also hold
a client cocktail reception Monday April 16 at the Loews Philadelphia Hotel, Millennium Hall.

Commenting on Willis’ presence at this year’s RIMS, Joe Plumeri, Chairman and CEO Willis Group Holdings said
“This conference comes at a critical time as organizations face new challenges and a new landscape
of risk. Today’s risk managers need innovative strategies to effectively navigate the current environment. They are
seeking solutions that will help them build resilience for their organizations over the long-term, rather than
simply transfer risk in a year-end, year-out transaction.”

“Willis is proud to be a part of the RIMS experience and proud to be a true
partner to the insurance buying community. We are excited to share Willis’ powerful industry expertise and
we encourage visitors to join us at the Willis booth or coffee hub,” Plumeri added.

Willis Group Holdings plc is a leading global insurance broker. Through its subsidiaries, Willis develops and delivers
professional insurance, reinsurance, risk management, financial and human resource consulting and actuarial services to corporations, public
entities and institutions around the world. Willis has more than 400 offices in nearly 120 countries,
with a global team of approximately 17,000 employees serving clients in virtually every part of the
world. Additional information on Willis may be found at www.willis.com.